Monday Medical: Can diabetes be prevented?

As a pastry chef, Amy was doubly concerned when she learned that her mother had developed Type 2 diabetes - concerned about her mother and concerned about herself.

Amy was aware that Type 2 diabetes runs in families. Like her mother, she seriously was overweight, and she recently had been told that she has pre-diabetes - elevated blood sugar, but not high enough to be considered a diagnosis of Type 2 diabetes.

"My job requires that I spend a good part of every day tasting very rich, sweet foods," she said. "If I were to get diabetes, I figured my career would be finished."

Actually, her doctor assured her that her occupation was much less of a hazard than her weight and lifestyle. Although Type 1 and Type 2 diabetes are characterized by high levels of glucose (or sugar) in the blood, sugar itself does not cause diabetes.

Virtually all carbohydrates a person eats are converted into glucose when they enter the blood stream. With the help of insulin produced by the pancreas, glucose then is taken into cells to be used as energy.

Type 1 diabetes develops when the pancreas becomes unable to produce insulin. Type 2 diabetes, representing 90 to 95 percent of all cases, usually occurs because cells become less efficient at using insulin, a condition known as insulin resistance. Although the pancreas continues to produce insulin, it is not enough to keep blood glucose levels in check.

Type 2 diabetes is more likely than Type 1 to be inherited. In addition to family history, risk factors include obesity and a sedentary lifestyle. For many years, doctors have advised patients who are at risk for diabetes to lose weight and become more physically active.

Results from the Finnish Diabetes Prevention Study confirmed this in 2001. Among more than 500 overweight people with pre-diabetes, lifestyle changes aimed at moderate weight loss (averaging about seven pounds) through diet and exercise resulted in a more than 50 percent lower risk for developing Type 2 diabetes.

Even more convincing and detailed evidence was published a year later with results from the U.S. Diabetes Prevention Program (DPP), a study involving 3,234 overweight people with pre-diabetes. One goal of the study was to see if an oral diabetes medication could prevent or delay the onset of Type 2 diabetes.

The study participants who took the medication indeed did have a reduced risk of developing diabetes compared to those taking a placebo. Participants in the lifestyle intervention group, however, did even better.

The lifestyle goals, now recommended as a prevention plan for people with pre-diabetes, were simple:

- weight loss of about 7 percent of body weight maintained throughout the study;

- at least 150 minutes a week of moderate physical activity at an intensity level similar to that of brisk walking;

- a low-fat diet with calories reduced enough to achieve and maintain the desired weight loss.

Those who followed this lifestyle intervention had a 58 percent reduced risk of developing Type 2 diabetes compared to 31 percent for those treated with the medication, called metformin.

Follow-up studies have concluded that weight loss was the key and that it was accompanied by increased production of insulin and better insulin sensitivity in body cells.

The level of support that study participants received in order to reach their goals is not always realistic in a nonresearch environment. However, many resources are available to help people with pre-diabetes get started and stick with lifestyle changes.

It is important for people with pre-diabetes to understand that any successful effort to prevent diabetes is a first step. A large percentage of patients who develop diabetes die from heart disease.

DPP participants showed reduced blood pressure, lower LDL cholesterol and triglycerides and a reduced risk of developing the metabolic syndrome. All of these health improvements decrease the chances of heart disease and early death or disability.

An estimated 57 million Americans have pre-diabetes, and there is evidence that many long-term health consequences already are developing in these persons. It's never too late - or too early - to do something about it.